Valve for rock drills



Sept. 2, 1930;

W. A. SMITH. JR

VALVE FOR ROCK DRILLS Filed Sept. 7, 1928 INVENTOR. m'lliam 1.52210'21105:

BY m

H15 ATTORNEY 7 4% w flp Patented Sept. 2, 1930 UNITED STATES PATENT OFFICE WILLIAl'vI A. SMITH, 311., OF IBHILLIPSBURG, NEW JERSEY, ASST GNOR TO INGERSOI L- BAND COMPANY, OI JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY VALVE roR ROCK DRILLS Application filed September 7, 1928. SerialNo. 304,562.

This invention relates to rock drills, but more particularly to a distributing valve for fluid actuated rock drills ofthe hammer type.

The object of the invention is to obtain 'a light-weight valve capable of a quick and positive action for distributing the pressure fluid to the ends of the rock drill cylinder.

Other objects will be in part obvious and in part pointed out hereinafter.

In the accompanying drawings illustrating the invention and in which similar reference characters refer to similar parts,

' Figure l is a sectional elevation of a portion of a rock drill having the invention applied thereto, a I

Figure 2 is a transverse view-taken through Figure 1 on the line 22 looking in the direction indicated by the arrows, and

Figure 3 is a perspective view of the valve.-

Referringto the drawings, the invention is shown embodied in a rock drill A having a cylinder B in which is disposed-areciprocatory hammer piston C. The cylinderB is provided with a pair of free exhaust ports B controlled by the piston .G. 'In the front end of the cylinder B is a front rcylinder washer D iha-ving-a bore E to slidably receive an extension F of the piston C. .7

The rock drill A illustrated isone in which it is intended to rotate the working imple ment (not shown) for .each blow of the ham mer piston-C. The rock .drill is accordingly provided with rotation mechanism comprising a rifle bar G which may slidably interlock with the piston C in a well .known {manner. The rifle barG has a head H which lies in the rearward end of the cylinder B and carries the usual spring pressed pawls J for engagement with a toothed rotation ratchet K. The rotation ratchet K may be secured against rotation with respect to the cylinder B in any suitable manner. a

On the rearward end of the Ycylinder B is disposed aback head L which partly extends into the cylinder and may lie-secured thereto by means of spring pressed side bolts (not shown). Among other functions, ,the back head L acts as a housingfor a rotary throttle 50 valve 0 ins. valve chamber]? forcontrolling the admission of pressure fluid from a source of supply into the rock drill.

The throttle valve O may be provided with the usual lever Q, for its manipulation and has a central chamber R into which pressure fluid from a hose or other suitable conduit may be constantly admitted. In the wall of the throttle valve 0 is a port S which, when the throttle valve is in its open position, registers witha passage T in .the back head lead.-

ing to a supply reservoir U also in .the back head L.

The back head L in this instance seats directly on the rotation ratchet K and is provided with a projection V on which may be pressed or otherwise secured a ring plate W which also seats on the rotationratchet Kand acts as an abutment for the rearwardend of .outer periphery with the wall .of the cylinder B. The plate X interposed between the plate Y and the rotation ratchet K is likewise in body engagement with the cylinder B whereby said plate, like the plate Y, is centralized in the cylinder. On the plate X is a forwardly extending projection b which may seat on the plate Y and is of smaller diameter than the flange Z to form an annular valve chamber 0 between the outer surface at and the inner surface 6 of the projection b and the flange Z respectively.

The valve chamber 0 is constantly supplied with pressure fluid which is conveyed thereto through supply passages f leading from the supply reservoir U to the valve chamber and are preferably formed in the rotation ratchet K and the plate X.

Leading from the valve chamber to the rearward end of the cylinder are rearward inlet passages 9 having their inlet openings or ports h in the surface d of the projection Z). The passage 9 in this instance extends through both the projection Z2 and the plate Y. The admission of pressure fluid to the front end of the cylinder is efiected through an inlet passage 7' in the cylinder B and through a port in the flange Z which affords communication between the valve chamber a and the inlet passage 7'. The ports 7L and 7c preferably lie in the same transverse plane. The distribution of pressure fluid from the valve chamber 0 to the ends of the cylinder is effected by a valve 0 disposed in the annuvalve chamber 0. The valve 0 in this instance consists of a resinent ring adapted to expand and contract in the valve chamber 0 to control the ports 7L and 7c. The valve 0 is split as at 7) and the ends (1 of the valve are suitably spaced to lie on opposite sides of a pin 1". The pin 1" is preferably seated in the projection Z) and extends across the valve chamber 0 to form an abn :rinent for the ends 9 of the valve for holding the valve 0 against rotary movement in the valve chamber 0.

The surfaces (Z and c in this instance constitute seating surfaces for the valve. They are formed around the ports 70 and 7t respectively. Between adjacent seating surfaces (Z are grooves s for conveying pressure fluid from the grooves t above the seating surfaces (Z to grooves 14 in the projection 6 below the seating surfaces (Z. In like manner, grooves 11 are formed in the flange Z between the seating surfaces 6 for conveying pressure fluid from grooves 4.0 above the seating surfaces 0 to grooves :0 formed below the seating surfaces 0. As a result of this construction, the seating surfaces are of smaller width than the valve 0 and considerable areas on both sides of the valve 0 will therefore be exposed to live pressure fluid at all times.

The operation of the device is as follows: lVith the throttle valve in the open position illustrated, pressure fluid entering the sup ply chamber U will flow through the supply passages f and the valve chamber 0. lVith the valve expanded to the position illustrated, pressure fluid will flow through the chamber between the inner surface of the valve and the seating surfaces (l, thence through the inlet passages 9 into the rearward end of the cylinder to impel. the piston C forwardly.

During the forward stroke of the piston C, said piston C will cover the exhaust port l3 and air in the front end of the cylinder will then be compressed and flow through the front inlet passage and the port 70 to act against the outer surface of the valve 0. As the piston proceeds in a forwardly direction, the exhaust ports B will be uncovered and there will be a sudden drop of pressure fluid on the inner surface of the valve 0. Then this occurs the compression acting against the outer surface of the Valve, tc-

gether with the live pressure fluid acting against the outer surface on an area equal to the heighth of the grooves w and 00 will cause the valve 0 to contract and seat against the seating surfaces (Z to cut off the supply of pressure fluid to the rearward end of the cylinder.

in the position of the valve, as above described, the inlet ports 7.: will be in communication wlth the valve chamber 0 and pres:- sure fluid will flow through these ports and the inlet passage 7' to the front end of the cylinder to return the piston to its initial position. During the rearward travel of the piston. the exhaust ports B will be covered by the piston and from then on the air in the rearward end of the cylinder will be compressed. Such compression flowing through the inlet passages will act against the inner surface of the valve 0. At the same time those portions of the inner .urface of the valve adjacent the grooves It and a will also be exposed to live pressure fluid tending to again expand the val e 0. When the piston C uncovers the exhaust ports B durin 51- the rearward stroke of the piston, the sudden drop in pressure on the outer surface of the valve will enable the compression and live air acting against the inner surface of the valve to again expand the valve 0 to its initial position, thus completing the cycle of operations.

I claim:

1. In a fluid actuated rock drill, the combination of a cylinder and a piston. an exhaust port for the cylinder. a valve chest having an annular valve chamber. inlet passages leading from the valve chamber to the cylinder, and a resilient ring valve adapted to expand in the valve chamber for controlling the inlet passages.

2. In a fluid actuated rock drill. the combination of a cylinder and a piston. an exhaust port for the cylinder. a valve chest having an annular valve chamber. an inlet passage leading from one side of the valve chamber to the rearward end of the cylinder, an inlet passage leading from the opposite side of the valve chamber to the front end of the cylinder, and a resilient ring valve adapted to expand and contract in the valve chamber for controlling the inlet passages.

I 3. In a fluid actuated rock drill. the combination of a cylinder and a piston. an exhaust port for the cylinder, a valve chest having an annular valve chamber, inlet passages leading from one side of the valve chamber to the rearward end of the cylinder, inlet passages leading from the opposite side of the valve chamber to the front end of the cylinder, a resilient ring valve adapted to expand and contract in the valve chamber for controlling the inlet passages. and supply passages opening into the valve chamber for lllS constantly conveying pressure fluid to both sides of the ring valve.

4. In a fluid actuated rock drill, the combination of a cylinder and a piston, an exhaust port for the cylinder, a valve chest comprising a pair of plates having projections lying in the same transverse plane and spaced with respect to each other to form an annular valve chamber, inlet passages leading from the valve chamber to the ends of the cylinder, and a resilient split ring valve expanding and contracting in the valve chamber to control the inlet passages.

5. In a fluid actuated rock drill, the combination of a cylinder and a piston, an exhaust port for the cylinder, a valve chest in the cylinder comprising a pair of plates held in coaxial relationship by the cylinder, a flange on one plate, a projection on the other plate lying in the same transverse plane as the flange and cooperating with said flange to form an annular valve chamber, inlet passages leading from opposite sides of the valve chamber to the ends of the cylinder, a supply passage in the valve chest constantly c0nveying pressure fluid to the ends of the valve chamber, and a resilient split ring valve expanding and contracting in the valve chamber to control the inlet passages.

so In testimony whereof I have signed this specification.

WILLIAM A. SMITH, JR. 

